22 May
2000
22 May
'00
5:22 p.m.
> Anyway, some parts have become scarce, so I would
have to use
substitutes.
For example,
Jameco no longer carries the 8T97 buffer/driver. As I recall
the 8T97 is an LS373 without the inverter on the gate *and* is faster and
I thought that the 74LS367 and 74LS368 (the latter being the inverting
one) were almost direct substitutes. I think the 8Txx parts can drive a
heavier load, but I doubt if this will cause problems in an Altair/Imsai The '373 is an octal transparent latch (with
3-state outputs) and is not
the same thing at all.
the '373 wasn't available when the altair was new.
> has a higher drive current. I've heard that
the MC6887 is a sub, but I
can't
> find a datasheet on it.
>
> The 8101 dual-port 256bx4 RAM is no longer available, but Jameco has a
5101
> which looks like a likely sub. I would forego this
type for a larger
SRAM,
That would work, the difference is the 5101 is cmos and the 8101 is mos.
I can't find the 8101 on any of the S100 card
schematics I've looked at,
so I wonder what on earth it was used for.
try 2101. the first ram card was a 256byte one using 256x4 parts if
memeory serves.
The denser cards were 2107/TMS4060 4kx1 Dram based.
He may have meant seperate Input and output like the 2102 (1kx1).
Allison